It is not easy to learn a new language or musical skill since most people do not have a good learning environment for enhancing one's learning efficiency. Learning is the acquisition and development of memories and behaviors that can be conceived as the product of experience. In psychology, habituation is an example of human learning process in which there is a progressive diminution of behavioral response probability with repetition of a stimulus. For instance, by getting used to a language through listening to it all the time is the way how we learn our first language, i.e. our mother tongue. In fact, language is the expression of human communication through a series of patterns which includes systematic, conventionally used signs, sounds, gestures, or marks that convey understood meanings within a group or community. It is required for a person to hear and practice such patterns in a repetitive manner so as to master the language. However, learning a foreign language can be a frustrating task since most people simply do not have the luxury of living in a foreign-language-speaking environment or having a foreigner to repeat a phrase again and again. In that case, those language learning machines currently available on the market will be our second best choice for learning foreign language.
Most of those language learning machines currently available on the market are almost identical in most respects, such as playing audio files, playing musical files, playing a particular segment of the playback repeatedly, adjusting playing speed, performing a test, and so on. It is noted that a student playing a learn-teaching material on one of the aforesaid conventional language learning machines can only stop, pause or repeat the playing of the learn-teaching material, but is not able to change the designed learning tempo of the learn-teaching material, so that the learning efficiency can be adversely affected as the learning tempo of the student may not match with the designed learning tempo of the learn-teaching material.